A recent study published in the journal Geology details the surprising discovery of a colony of ancient Adélie penguins, preserved in remarkable condition thanks to the region’s climate. Some of the remains were in such good nick that they appeared fresh to lead researcher Steven Emslie, a confounding finding given there are no records of an extant penguin colony at Cape Irizar since the first explorers (including Robert Falcon Scott) came to the Ross Sea in 1901-1903.
Among the remains was a glut of penguin chick bones, which were scattered among guano stains left by the droppings of penguins at some point in the Cape’s history. Emslie and his team even came across some complete chick carcasses still with feathers falling away and others complete mummies. Perplexed by the inconsistencies of their findings with the Cape’s record, they collected samples for radiocarbon dating to try and make sense of what they were looking at.
The analyses revealed that Cape Irizar had played host to breeding penguins on at least three occasions, with the last one ending around 800 years ago. It’s possible this occupation came to an end as a result of increasing snowfall as it was at around this time the Little Ice Age was kicking in. The "fresh" remains found by Emslie’s team were likely buried in snow when they died and preserved intact until recent snowmelt revealed them once more on the surface.
Snowmelt is being seen across the region as global warming has pushed the annual temperature of the Ross Sea up by around 1.5 – 2.0°C (34.7 – 35.6°F) since the 1980s. The effects have been observed via satellite imagery, showing more and more of the cape emerging from beneath its icy cover.
“Overall, our sampling recovered a mixture of old and what appeared to be recent penguin remains implying multiple periods of occupation and abandonment of this cape over thousands of years,” explained Emslie in a statement. “In all the years I have been doing this research in Antarctica, I've never seen a site quite like this."
"This recent snowmelt revealing long-preserved remains that were frozen and buried until now is the best explanation for the jumble of penguin remains of different ages that we found there."